This invention relates to a method and apparatus for cleaning shredded scrap such as produced by an automobile shredder or by other suitable shredders for metal articles. The shredded scrap discharged from an automobile shredder contains a mixture including ferrous and non-ferrous scrap together with particulate material which includes dust and dirt and shredded cushions, fabric, and other non-metallic material from the automobile. Before the metallic scrap can be processed, it is desirable to remove most of the non-metallic particulate material. In the past, this has been done by conveying the mixed scrap out of the shredder on a bar grid through which an air stream is sucked to separate some of the non-metallic particulate material from the metallic fragments, the bar grid feeding the material by gravity onto a second conveyor. The particulate material in the air stream is separated out in a series of cyclonic separators, three of which are required in the conventional system to adequately clean the shredded scrap.
Water is used in this prior art shredder to hold down the dust, as otherwise there would have been substantial dust leakage to the atmosphere.
The principal object of this invention is to provide a simpler and more efficient method and apparatus for cleaning shredded metal scrap while effectively preventing leakage of dust and pollution of the air.
A further object of the invention is to provide a method and apparatus in which use of water in the shredder is eliminated so as not to interfere with the heat generated in the shredder, and wherein said heat is utilized in the duct work to prevent the buildup of particulate material in the ducts leading from the shredder.
A further object of the invention is to provide a method and apparatus for cleaning scrap wherein all of the air for the system is picked up at the shredder together with dust from the shredder, thereby eliminating any dust leakage at the shredder.
Other objects and advantages of the invention will become apparent to those skilled in the art from the disclosure herein.